A320neo or ceo? Engines, Sharklets and other identifying features

An A320 taxis up to the fence, you know the livery, you cannot read the registration yet – but is it a neo or a ceo? The question is one of the most common in plane spotting, because both generations have flown side by side for years, often with the same airline. Fuselage, cockpit and tail are practically identical. Anyone who wants to tell the A320neo and ceo apart therefore needs a trained eye for a few details: engines, wingtips and, on the A321, the door layout. This guide shows you what to look at, in what order, and where the typical traps lie.

A320neo or ceo: the short answer

The most reliable way to recognize the generation is the engine nacelles. The neo carries much larger, almost perfectly round nacelles that extend far ahead of the wing’s leading edge. The ceo has slimmer nacelles that look smaller in relation to the fuselage. The second feature is the wingtips: small, triangular wingtip fences exist only on the ceo. Sharklets, on the other hand, are found on both generations – so they prove nothing. The type code removes the last doubt: A20N stands for the A320neo, A320 for the ceo.

The name already tells you where the difference lies. “neo” stands for New Engine Option, “ceo” for Current Engine Option. Airbus kept the proven airframe of the Airbus A320 and mainly fitted new engines. The first flight of the A320neo took place on September 25, 2014, and the first aircraft went to Lufthansa on January 20, 2016. By then, the original A320 had already been flying for almost three decades – its first flight dates from February 22, 1987.

Feature 1: The engines

The engines are the core of the modernization and therefore also the best identifying feature. Modern engines become more efficient by pushing more air past the hot core – for that they need a bigger fan and therefore a bigger nacelle. That is exactly what you see at the fence.

Engine	Generation	Manufacturer	Fan diameter (approx.)	What you see
CFM56-5A / -5B	ceo	CFM International	1.73 m	round inlet, engine core with exhaust cone sticks out behind the fan cowl
IAE V2500	ceo	International Aero Engines	1.61 m	slim, elongated nacelle that extends farther back
CFM LEAP-1A	neo	CFM International	1.98 m	very large, round nacelle, far ahead of the wing
PW1100G-JM	neo	Pratt & Whitney	2.06 m	very large, round nacelle, geared turbofan

The diameters refer to the fan, not the outer nacelle – which is somewhat larger in each case. The jump from around 1.6 to 1.7 meters to around 2 meters is still so clear that after a few comparisons you see it at first glance.

What the neo nacelle looks like

The effect is most striking from the front and from an oblique front angle. On the neo, the inlet fills a large part of the space between the underside of the wing and the ground, and the nacelle looks massive in relation to the fuselage. From the side, you notice how far it extends ahead of the wing’s leading edge. Some airlines also write “neo” on the nacelle – a gift for spotters, but not a requirement. Do not rely on the lettering always being there.

What the ceo nacelles look like

On the ceo you have two nacelle shapes, and it is worth knowing both. The CFM56-5 works with separate exhaust streams: the fan cowl ends a bit ahead of the rear of the engine, and behind it you see the narrower engine core with its exhaust cone. The thrust reverser of the CFM56-5 works with swiveling doors, whose outlines you can often recognize in photos as panels in the nacelle cowling. The V2500, by contrast, has a slimmer, longer-looking nacelle that extends farther back. Both are clearly smaller than the neo engines, though. If you want to dig deeper into engine designs, read the guide Identifying aircraft engines.

LEAP or Pratt & Whitney?

Within the neo, it gets harder. Both engines are large and round, and the PW1100G fan is only a few centimeters larger. With the naked eye, you can hardly tell the two apart reliably. The easiest route is the model designation: Airbus encodes the engine manufacturer in the type number. On the A320neo, A320-251N stands for the LEAP-1A and A320-271N for the PW1100G. On the A321neo, the counterparts are A321-251N and A321-271N. You can find the designation for a registration in fleet databases, for example via Planespotters.net.

By the way, the choice of engine has a practical side effect for spotters: because of extensive inspections on the PW1100G, many aircraft with this engine have been grounded at some airlines in recent years. If an airline temporarily operates more ceos than neos, that may be the reason.

Feature 2: The wingtips

The wingtips are the second feature that many people check first – and the one most often misread. There are three variants:

• No wingtip devices: That applied only to the earliest A320-100s. This version is historical and you will not run into it in everyday spotting.
• Wingtip fences: small, triangular surfaces that point up and down at the wingtip. They are typical of the A320-200 and the other ceo models before Sharklets were introduced. Fences always mean ceo.
• Sharklets: large, upward-curved wingtips that grow smoothly out of the wing. On the neo they are standard, on the ceo an option that Airbus introduced in 2009. The first ceo with Sharklets was delivered to Indonesia AirAsia in December 2012.

A simple rule follows: fences rule out the neo, Sharklets do not rule out the ceo. An A320 with Sharklets can therefore be either, while one with fences is guaranteed to be a ceo. Which wingtips exist on other types is shown in the guide Winglets, Sharklets, Split Scimitar and raked wingtips.

Feature 3: The door layout of the A321

On the A320 and the A319, the door layout does not help you, because ceo and neo have the same arrangement of doors and emergency exits. On the long A321, it is different. The A321ceo always has four large pairs of doors – at the front, directly ahead of the wing, directly behind the wing and at the rear – and no small overwing emergency exits.

The A321neo is also available in the Airbus Cabin Flex variant. Here the pair of doors ahead of the wing is omitted, and instead two pairs of emergency exits sit over the wing, with the door behind the wing located farther back. A long Airbus narrowbody with overwing emergency exits is therefore practically always a neo. The reverse does not hold: there are also A321neos with the classic door layout. The long-range versions A321LR and A321XLR also belong to the neo family. How to tell the A318, A319, A320 and A321 apart in the first place is explained in the guide Telling the A320 family apart.

Feature 4: Type code and model designation

When your eye is unsure, technology helps. Live maps and flight tracking services show the ICAO type code for every flight, and it is unambiguous:

Model	ceo type code	neo type code	ceo model designation (examples)	neo model designation
A318	A318	–	A318-111, A318-112	no neo version
A319	A319	A19N	A319-111, A319-132	A319-151N, A319-171N
A320	A320	A20N	A320-214, A320-232	A320-251N, A320-271N
A321	A321	A21N	A321-211, A321-231	A321-251N, A321-271N, -NX variants

The ceo designations also encode the engine manufacturer: a 1 in the second position of the number stands for CFM56, a 3 for the V2500, and on the A318 a 2 for the PW6000. An A320-214 therefore flies with CFM56-5B, an A320-232 with V2500. On the neo, the 5 indicates the LEAP and the 7 the PW1100G. You can find more on the system in the article ICAO type codes explained. How to look up a registration in the database and then track the aircraft is described in the guide Tracking an aircraft by registration.

Step by step at the fence

With the four features, identification becomes routine. The order matters, because it saves you time:

The typical mix-ups

Late ceos with Sharklets

The most common trap. An A320ceo from the later build years with Sharklets looks very modern at first glance. Consistently look at the nacelles here: on the ceo they are slim despite the Sharklets. The CFM56-5B in particular, with its visible engine core behind the fan cowl, quickly gives away the older generation.

Flat perspective on approach

On an approach from obliquely below or straight from the front, perspective distorts the proportions. The nacelles then look large on both generations. Comparing with the fuselage diameter helps: on the neo, the inlet comes noticeably closer to that measure than on the ceo.

A320neo or Boeing 737 MAX

The 737 MAX also carries large engines and striking wingtips. But you separate the families by nose, cockpit windows and tail – the guide Telling Airbus and Boeing apart explains that. How to tell the generations apart within the 737 is shown in Boeing 737 Original, Classic, NG and MAX: how to tell them apart.

Mixed fleets at the same airline

Many airlines fly both generations in parallel and in identical livery, such as easyJet or Wizz Air. The livery then does not help you, but the engines do.

Where to see both generations side by side

The A320 family is part of everyday life at almost every large European airport, so you do not have to travel far. Hamburg is especially exciting: aircraft of the A320neo family are built at the Finkenwerder plant, and at Hamburg Airport you can see numerous ceos and neos in scheduled service from the Affenfelsen or the observation deck. What there is to see around the plant is covered in the guide Spotting at Airbus Finkenwerder. You can find more about the manufacturer itself in the profile of Airbus.

A good practice approach: in one day, photograph as many A320s as possible from the side, note the registration and your assessment for each picture, and compare it with the database in the evening. After two or three sessions, you will usually recognize the generation at first glance. For an introduction to type identification in general, the guide Identifying aircraft types for beginners is recommended.

Conclusion

The A320 family is the best training ground for looking closely: two generations, four engines, almost identical airframes. Anyone who gets into the habit of looking at the nacelles first and then at the wingtips is almost always right. And if not, the registration in the photo provides the answer – at the latest in the evening when you sort your sightings.